The objective of this research program is to demonstrate the feasibility and develop towards commercialization a low-cost, reliable detector to monitor ethylene oxide (EtO) down to the 0.1 ppm level. The detector would have a response time of one minute or less and would feature a gas chromatograph (GC) column coupled with a solid state combustible gas sensor. Air drawn as part of the sample would act as the GC carrier gas, thus eliminating bottled gases. EtO is an effective gas sterilizing agent of heat-sensitive medical products and is widely used in hospitals and other health care facilities. The highly reactive nature of EtO also means that the exposure of personnel involved in sterilization operations needs to be close)y regulated. EtO has been shown to be a mutagen; to be able to cause chromosome damage in plants, animals, and man; to be toxic to both male and female reproductive function in several animal species; to be possibly toxic to human reproductive function; to be a proven animal carcinogen; and to possibly be a carcinogen to man. The proposed detector would allow for the continuous monitoring of EtO to the NIOSH recommended exposure levels.